1. Field of the Invention
This invention relates to a mining machine, and more particularly, to a continuous mining machine having roof support apparatus operable to permanently support a mine roof at predetermined locations above the mining machine while the mining machine is continuously advanced into a face of the mine to dislodge material therefrom. The mining machine furhter includes gathering head extensions positioned laterally on the front end of the mining machine gathering head operable to deflect dislodged material from a floor of the mine onto the mining machine.
2. Description of the Prior Art
It is well known in underground mining operations to provide a mining machine which is designed to continuously advance along a floor of the mine and dislodge material from a mine face. The dislodged material is conveyed rearwardly of the mining machine for further treatment. However, it is not uncommon for the mining operation to be stopped at various times and the mining machine withdrawn from the mine face in order to install supports in the mine roof above the mining machine.
Various types of roof bolters have been utilized for movement into the entry adjacent the mine face for installation of roof bolts in the mine roof to support the roof adjacent the face. U.S. Pat. No. 2,771,273 discloses a portable roof drilling and bolting machine operable to install roof bolts in a mine roof. U.S. Pat. Nos. 4,094,158 and 4,097,854 each disclose mine roof bolting apparatus which includes a temporary roof support to insure the stability of the roof during installation of roof bolts.
U.S. Pat. No. 3,268,258 discloses a surge device that is positioned behind a continuous miner having roof bolters mounted on the sides thereof. The surge device is moved under the tail conveyor of the mining machine a sufficient distance to allow the mining machine to continue to advance while the surge device remains stationary and the roof bolters set bolts in the roof. The surge device is then advanced to its original position under the tail conveyor of the mining machine.
U.S. Pat. No. 3,493,058 discloses a roof drilling and bolting apparatus which is mounted on the side of a continuous mining machine. The apparatus includes a carriage with a bolter mast, a roof jack and a floor jack mounted thereon. The roof jack and floor jack are arranged to provide temporary support between the roof and floor of the mine and to lock the bolter carriage in a fixed position during installation of the roof bolts. The bolter apparatus remains stationary during installation of the roof bolts as the mining machine continues to dislodge material from the mine face.
U.S. Pat. No. 3,813,126 discloses a continuously operable underground mining vehicle that includes temporary roof supporting apparatus, and rock cutting apparatus mounted on an end of a mobile frame. Hydraulic jacks are mounted on the mobile frame to provide temporary roof support above the vehicle. A pair of roof bolters are disposed between the jacks to provide permanent support for the area over the vehicle. A water jet nozzle is movably mounted in front of the vehicle to dislodge material from the mine face as the roof bolts are installed.
U.S. Pat. No. 4,131,317 discloses a mining machine having roof support apparatus for continuously supporting the mine roof as material is dislodged from the mine face and provided to a conveying apparatus which removes the dislodged material rearwardly from the face. Roof drilling units associated with each of the roof supporting units permit simultaneous drilling of bore holes in the roof and installation of roof bolts while the mining machine is dislodging material from the face.
U.S. Pat. No. 4,199,193 discloses a mining machine having a main frame with a front portion and a rearwardly extending portion, and cutter heads disposed for movement across the front portion for dislodging material from a mine face. A conveyor system extends across the front of the main frame and along the rearwardly extending portion for carrying dislodged material from the mine face. Forward roof support jacks are attached to the main frame to provide temporary roof support. Rear roof support jacks positioned on either side of the rearwardly extending frame portion are connected to the front portion of the frame by cylinders and also provide temporary roof support. Roof bolters are attached to the rear roof support jacks for installing roof bolts as the machine advances.
U.S. Pat. No. 4,310,197 discloses a mining apparatus and a bolting apparatus positioned in a mine entry adjacent a mine face under a temporary roof support. The temporary roof support is comprised of cross beams supported by beam jacks. The mining apparatus removes material from the mine face to advance the mine face. The bolting apparatus installs roof bolts to provide a permanent roof support. The bolting apparatus includes lowering means for lowering the temporary roof supports after the roof bolts are installed.
A continuous mining machine having roof bolting apparatus is illustrated in an article appearing in COAL AGE magazine, November, 1986, on page 17, entitled "Fairchild Seeks New Financing For Its Umbrella Miner." The illustrated mining machine consists of a main frame having a front portion and a rearwardly extending portion. Cutter heads are positioned on the main frame front portion for dislodging material from a mine face. Roof bolter assemblies are positioned on each side of the rearwardly extending portion for providing roof support as the mining machine advances into the mine face. A conveyor assembly is pivotally connected rearwardly of the mining machine for receiving material dislodged from the mine face.
Although the prior art devices suggest apparatus for installing roof bolts in a mine roof as a mining machine is advanced into the face of the mine, there is a need for an improved mining machine capable of providing temporary roof support above the mining machine while installing permanent roof supports in the mine roof as the mining machine continuously advances to dislodge material from the mine face. The apparatus must be capable of standing independently of the mining machine as the mining machine advances into the mine face. Longitudinal, vertical and lateral freedom between the mining machine and the free-standing roof support apparatus permits simultaneous installation of roof supports and removal of material from the mine face.
It is also known to provide mining machines with material gathering apparatus for collecting loose material from the mine floor adjacent the mine ribs and directing the collected material onto the mining machine.
U.S. Pat. No. 4,199,193 discloses a continuous mining machine which includes a T-shaped main frame having a front portion and a rearwardly extending portion. Rib cleaners are pivotally connected to the sides of the main frame front portion and are urged outwardly by hydraulic cylinders to contact the adjacent mine ribs and channel loose material onto a conveyor mounted on the main frame.
U.S. Pat. No. 4,296,856 discloses a mining machine which includes a mobile body having an endless conveyor for conveying rearwardly on the body material dislodged by the mining machine. A gathering platform extends forwardly from the conveyor. Oscillating gathering arms positioned laterally of the receiving end of the conveyor on the gathering platform feed dislodged material onto the receiving end of the conveyor. Deflector plates are pivotally mounted on the gathering platform to deflect loose material deposited on the mine floor along the mine wall onto the gathering platform. The deflector plates are biased laterally outwardly from the gathering platform by a spring to maintain the deflector plates in contact with the mine wall.
While the prior art mining machines suggest apparatus for collecting loose material from a mine floor, there is a need for an improved gathering device for a continuous mining machine in which the side edge portions of the gathering device are maintained in a position relative to the mine wall to direct loose material on the mine floor at the mine wall onto the gathering platform as the mining machine advances through the mine. The gathering device must be capable of linear movement on the gathering platform to prevent the gathering device from being damaged by protrusions on the mine wall.